In the field of views for missile systems using a laser guidance beam for guiding missiles, it is known to use a collimator for aligning the guidance beam with an alignment mark in a viewing device. The viewing device can be a camera or another device that continuously can detect visible or non-visible light and that can present the detected result. The alignment mark in the viewing device marks the position of the guidance beam in the viewing device so that an operator can aim the guidance beam towards a target by aiming the alignment mark towards the target accordingly. The alignment mark can be an electronically generated mark, for example in the form of a crosshair.
The collimator comprises a light detector and a number of light sources which can be detected by the viewing devices. The light sources must be able to produce visible light for the visible light viewing device and non-visible light for the non-visible light viewing device. The collimator may be fixedly attached to the sight or may be detachably attachable to the sight. In order for the sight to work it is imperative that the viewing device is calibrated to always know the trajectory of the guidance beam, i.e. the position of the guidance beam in the field of view of the viewing device has to be known. Hence, the viewing device, i.e. the alignment mark, and the lead guidance beam have to be aligned.
The problem of alignment can be solved by fixing the guidance beam in relation to the alignment mark, but this is an expensive and difficult operation because it puts high demands on both the quality of the materials used and the tolerances when manufacturing the sight.
Another solution to the problem of aligning is to use an adaptive/active collimator that can continuously adjust the alignment mark to the guidance beam. In the latter case it is known to use a detector for detecting an axis of symmetry of the guidance beam and a number of visible and non-visible light sources positioned at predetermined positions around the detector. The known positions of the light sources allow for calculation of the position of the alignment mark in relation to the axis of symmetry of the guidance beam. For this solution to work, a number of calculations have to be made, which consumes energy and computing recourses. Furthermore, the positions of the light sources relative the detector have to be known accurately, otherwise the alignment mark will be misaligned. The accuracy of the positions puts high demand on the parts involved in the assembly and the assembly operation itself.
Hence, there is a need for an alternative solution to the above, where the number of calculations can be lessened and where the assembly of the sight and collimator can be done in a more simple and robust way.